青藏高原30米地表覆盖数据（2010）

本数据包含两个数据文件，GLOBELAND30 TILES（原始数据）和TIBET_ GLOBELAND30_MOSAIC（镶嵌数据）。
原始数据下载自全球地表覆盖数据网站（GlobalLand3）（http://www.globallandcover.com），范围涵盖青藏高原及周边地区。原始数据分幅存储，为了便于用户使用数据，在分幅数据的基础上，我们使用Erdas软件对原始数据进行了拼接镶嵌。
全球地表覆盖数据（GlobalLand30）是国家863计划重点项目“全球地表覆盖遥感制图与关键技术研究”的科研成果，该数据利用美国陆地卫星影像（TM5、ETM+）和中国环境减灾卫星（HJ-1）影像数据，采用基于像素分类-对象提取-知识检核的综合方法提取而成。数据包括耕地、森林、草地、灌木、湿地、水体、苔原、人造覆盖、裸地、冰川和永久积雪10个一级地表覆盖类型，没有进行二级类型提取。在准确度评估方面，评估九种类型和超过150,000个测试样品。GlobeLand30-2010的整体精度达到80.33％。Kappa指标为0.75。
GlobeLand30数据采用WGS84坐标系，UTM投影，6度分带，参考椭球为WGS 84椭球。根据不同的纬度情况，采用2种分幅方式进行数据组织。在南北纬60°区域内，按照5°（纬度）×6°（经度）大小进行分幅；在南北纬60°至80°区域内，按照5°（纬度）×12°（经度）大小进行分幅，按照奇数6°带的中央经线进行投影。
GLOBELAND30 TILES：原始数据保留数据原貌，未进行处理。
TIBET_ GLOBELAND30_MOSAIC：使用erdas软件对原始数据进行镶嵌，参数设置使用默认值原始数据保留数据原貌，精度同下载网站。

This dataset contains two data files: GLOBELAND30 TILES (raw data) and TIBET_GLOBELAND30_MOSAIC (mosaicked data).

The raw data was downloaded from the GlobalLand3 website (http://www.globallandcover.com), covering the Qinghai-Tibet Plateau and its surrounding areas. The raw data is stored in tiled segments. To facilitate user access to the data, we performed mosaic stitching on the tiled raw data using Erdas software.

GlobalLand30 is a research outcome of the key project "Research on Global Land Cover Remote Sensing Mapping and Key Technologies" under China's 863 High-Tech Research and Development Program. This dataset was extracted using Landsat satellite images (TM5, ETM+) and China's Environmental and Disaster Reduction Satellite (HJ-1) imagery, adopting a comprehensive method integrating pixel-based classification, object-based extraction and knowledge-based verification. It includes 10 first-level land cover types: cropland, forest, grassland, shrubland, wetland, water body, tundra, artificial surfaces, barren land, glaciers and permanent snow cover, without secondary type extraction. For accuracy assessment, 9 types and over 150,000 test samples were evaluated. The overall accuracy of GlobeLand30-2010 reached 80.33%, with a Kappa coefficient of 0.75.

The GlobeLand30 data adopts the WGS84 coordinate system and UTM projection with 6-degree zones, with the reference ellipsoid being the WGS 84 ellipsoid. Two tiling schemes are used for data organization based on different latitudes: within the regions between 60° north and south latitude, tiles are sized at 5° (latitude) × 6° (longitude); for regions between 60° and 80° north and south latitude, tiles are sized at 5° (latitude) × 12° (longitude), projected using the central meridian of odd-numbered 6-degree zones.

GLOBELAND30 TILES: The raw data retains its original state without any processing.
TIBET_GLOBELAND30_MOSAIC: The raw data was mosaicked using Erdas software with default parameter settings, while the original data is retained in its original state, with the same accuracy as the download website.